bindings: Use Maybe APIs in V8ScriptRunner (part 1)

Source/bindings/core/v8/ScriptDebugServer.cpp

 /*
  * Copyright (c) 2010-2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 596 matching lines @@
 
 void ScriptDebugServer::ensureDebuggerScriptCompiled()
 {
     if (!m_debuggerScript.IsEmpty())
         return;
 
     v8::HandleScope scope(m_isolate);
     v8::Context::Scope contextScope(v8::Debug::GetDebugContext());
     const blink::WebData& debuggerScriptSourceResource = blink::Platform::current()->loadResource("DebuggerScriptSource.js");
     v8::Handle<v8::String> source = v8String(m_isolate, String(debuggerScriptSourceResource.data(), debuggerScriptSourceResource.size()));
-    v8::Local<v8::Value> value = V8ScriptRunner::compileAndRunInternalScript(source, m_isolate);
-    ASSERT(!value.IsEmpty());
+    v8::Local<v8::Value> value = V8ScriptRunner::compileAndRunInternalScript(source, m_isolate).ToLocalChecked();

[haraken, 2015/03/18 01:58:51]

Wouldn't it be better to use ToLocal and return early if the value is empty?

I'm asking this because in V8InjectedScriptManager.cpp, you don't use
ToLocalChecked but use ToLocal & early return. Given that any
compileAndRunInternalScript can potentially fail (e.g., if a worker termination
is requested), I'd prefer using early-return always (and avoid using
ToLocalChecked).

[bashi, 2015/03/18 02:33:11]

Will do.

     ASSERT(value->IsObject());
     m_debuggerScript.Reset(m_isolate, v8::Handle<v8::Object>::Cast(value));
 }
 
 void ScriptDebugServer::discardDebuggerScript()
 {
     ASSERT(!m_debuggerScript.IsEmpty());
     m_debuggerScript.Reset();
 }
 
@@ skipping 61 matching lines @@
 }
 
 void ScriptDebugServer::compileScript(ScriptState* scriptState, const String& expression, const String& sourceURL, bool persistScript, String* scriptId, String* exceptionDetailsText, int* lineNumber, int* columnNumber, RefPtrWillBeRawPtr<ScriptCallStack>* stackTrace)
 {
     if (!scriptState->contextIsValid())
         return;
     ScriptState::Scope scope(scriptState);
 
     v8::Handle<v8::String> source = v8String(m_isolate, expression);
     v8::TryCatch tryCatch;
-    v8::Local<v8::Script> script = V8ScriptRunner::compileScript(source, sourceURL, String(), TextPosition(), m_isolate);
-    if (tryCatch.HasCaught()) {
+    v8::Local<v8::Script> script;
+    if (!v8Call(V8ScriptRunner::compileScript(source, sourceURL, String(), TextPosition(), m_isolate), script, tryCatch)) {
         v8::Local<v8::Message> message = tryCatch.Message();
         if (!message.IsEmpty()) {
             *exceptionDetailsText = toCoreStringWithUndefinedOrNullCheck(message->Get());
             *lineNumber = message->GetLineNumber();
             *columnNumber = message->GetStartColumn();
             v8::Handle<v8::StackTrace> messageStackTrace = message->GetStackTrace();
             if (!messageStackTrace.IsEmpty() && messageStackTrace->GetFrameCount() > 0)
                 *stackTrace = createScriptCallStack(m_isolate, messageStackTrace, messageStackTrace->GetFrameCount());
         }
         return;
     }
-    if (script.IsEmpty() || !persistScript)
+    if (!persistScript)
         return;
 
     *scriptId = String::number(script->GetUnboundScript()->GetId());
     m_compiledScripts.Set(*scriptId, script);
 }
 
 void ScriptDebugServer::clearCompiledScripts()
 {
     m_compiledScripts.Clear();
 }
 
 void ScriptDebugServer::runScript(ScriptState* scriptState, const String& scriptId, ScriptValue* result, bool* wasThrown, String* exceptionDetailsText, int* lineNumber, int* columnNumber, RefPtrWillBeRawPtr<ScriptCallStack>* stackTrace)
 {
     if (!m_compiledScripts.Contains(scriptId))
         return;
     v8::HandleScope handleScope(m_isolate);
     v8::Local<v8::Script> script = v8::Local<v8::Script>::New(m_isolate, m_compiledScripts.Remove(scriptId));
     if (script.IsEmpty())
         return;
 
     if (!scriptState->contextIsValid())
         return;
     ScriptState::Scope scope(scriptState);
     v8::TryCatch tryCatch;
-    v8::Local<v8::Value> value = V8ScriptRunner::runCompiledScript(m_isolate, script, scriptState->executionContext());
+    v8::Local<v8::Value> value;
     *wasThrown = false;
-    if (tryCatch.HasCaught()) {
+    if (v8Call(V8ScriptRunner::runCompiledScript(m_isolate, script, scriptState->executionContext()), value, tryCatch)) {
+        *result = ScriptValue(scriptState, value);
+    } else {
+        if (!tryCatch.HasCaught())

[haraken, 2015/03/18 01:58:51]

Can this happen?

In V8BindingMacros.h, you're adding ASSERT(success || tryCatch.HasCaught()),
which means that tryCatch.HasCaught() is guaranteed to be true here.

[bashi, 2015/03/18 02:33:11]

Oh, I forgot to remove this. Will remove.

+            return;
         *wasThrown = true;
         *result = ScriptValue(scriptState, tryCatch.Exception());
         v8::Local<v8::Message> message = tryCatch.Message();
         if (!message.IsEmpty()) {
             *exceptionDetailsText = toCoreStringWithUndefinedOrNullCheck(message->Get());
             *lineNumber = message->GetLineNumber();
             *columnNumber = message->GetStartColumn();
             v8::Handle<v8::StackTrace> messageStackTrace = message->GetStackTrace();
             if (!messageStackTrace.IsEmpty() && messageStackTrace->GetFrameCount() > 0)
                 *stackTrace = createScriptCallStack(m_isolate, messageStackTrace, messageStackTrace->GetFrameCount());
         }
-    } else {
-        *result = ScriptValue(scriptState, value);
     }
 }
 
 } // namespace blink